Updated xcconfigs to allow setting of SDKROOT successfully to 10.4 / 10.5 and 10.6 (10.7 untested).
Added more build folders to .gitignore
Fixed compiler errors when compiling with SDKROOT > 10.4
Merge branch 'bugfix-10838' into release-6.0.1
Update submodules.
Remove atl headers from w32 externals
Merge branch 'bugfix-10853' into release-6.0.1
fix intersect detection with semi-transparent images
Fix gif with no repeatcount (i.e. -1) not animating when loaded
Comment previous change
Fixed bug 10837 - literals that look like numbers must eval as 'both' (string and number).
Fixed bug 10844 - incorrect evaluation of threshold parameter, should use ton() rather than ston().
added _internal resolve image [id] <id or name> relative to <object reference>

 This command resolves a short id or name of an image as would be used for an icon
 and sets 'it' to the long ID of the image according to the documented rules for resolving
 icons.

 'it' is set empty if the command fails to resolve the image which means it's not on any stack in memory.
Reduce stack load times due to image loading
Merge branch 'bugfix-10828' into release-6.0.1
Merge branch 'bugfix-10843' into release-6.0.1
Merge branch 'bugfix-10827' into release-6.0.1
Merge branch 'bugfix-10837' into release-6.0.1
Merge branch 'bugfix-10844' into release-6.0.1
Update submodules.
Merge commit 'd6e38f24803032ae18cea20490be189230d2a69b' into feature/_internalResolveImage
made style and error handling changes as required